Taylor Swift and MKTO perform their classic hit together at night two of Tay’s 1989 show in Boston.

“I first heard this song on the radio. It was all over the radio for like the last year, and I loved it so much that even though it was being played all the time, I needed to have it,” Swift said. “So I bought it and listened to it all the time. My friends and I would dance around to it because it’s like the most… it’s like the sweetest song a guy could write for a girl. It’s also so catchy, so danceable, and this duo is one of my favorite things out there. They’re incredibly cool people, so talented, and they’re about to sing ‘Classic’ for you.”